X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavformat%2Frtsp.c;h=56e5de27f8d821e4dd06216769979996f9edca5c;hb=34aadeaa2c2ae2e84abde3cca0a8b1392b8294ac;hp=d32f49ed4c53b3204dfde94fbac9383e10c125e5;hpb=67f5650a78de2567c58dbd7545434cc6d3ef9b7e;p=ffmpeg

diff --git a/libavformat/rtsp.c b/libavformat/rtsp.c
index d32f49ed4c5..56e5de27f8d 100644
--- a/libavformat/rtsp.c
+++ b/libavformat/rtsp.c
@@ -1103,7 +1103,7 @@ int ff_rtsp_make_setup_request(AVFormatContext *s, const char *host, int port,
                               int lower_transport, const char *real_challenge)
 {
     RTSPState *rt = s->priv_data;
-    int rtx = 0, j, i, err, interleave = 0;
+    int rtx = 0, j, i, err, interleave = 0, port_off;
     RTSPStream *rtsp_st;
     RTSPMessageHeader reply1, *reply = &reply1;
     char cmd[2048];
@@ -1120,8 +1120,11 @@ int ff_rtsp_make_setup_request(AVFormatContext *s, const char *host, int port,
     /* for each stream, make the setup request */
     /* XXX: we assume the same server is used for the control of each
      * RTSP stream */
+    port_off = av_get_random_seed() % (RTSP_RTP_PORT_MAX - RTSP_RTP_PORT_MIN);
+    /* even random offset */
+    port_off -= port_off & 0x01;
 
-    for (j = RTSP_RTP_PORT_MIN, i = 0; i < rt->nb_rtsp_streams; ++i) {
+    for (j = RTSP_RTP_PORT_MIN + port_off, i = 0; i < rt->nb_rtsp_streams; ++i) {
         char transport[2048];
 
         /*
@@ -1158,18 +1161,15 @@ int ff_rtsp_make_setup_request(AVFormatContext *s, const char *host, int port,
             }
 
             /* first try in specified port range */
-            if (RTSP_RTP_PORT_MIN != 0) {
-                while (j <= RTSP_RTP_PORT_MAX) {
-                    ff_url_join(buf, sizeof(buf), "rtp", NULL, host, -1,
-                                "?localport=%d", j);
-                    /* we will use two ports per rtp stream (rtp and rtcp) */
-                    j += 2;
-                    if (ffurl_open(&rtsp_st->rtp_handle, buf, AVIO_FLAG_READ_WRITE,
-                                   &s->interrupt_callback, NULL) == 0)
-                        goto rtp_opened;
-                }
+            while (j <= RTSP_RTP_PORT_MAX) {
+                ff_url_join(buf, sizeof(buf), "rtp", NULL, host, -1,
+                            "?localport=%d", j);
+                /* we will use two ports per rtp stream (rtp and rtcp) */
+                j += 2;
+                if (!ffurl_open(&rtsp_st->rtp_handle, buf, AVIO_FLAG_READ_WRITE,
+                               &s->interrupt_callback, NULL))
+                    goto rtp_opened;
             }
-
             av_log(s, AV_LOG_ERROR, "Unable to open an input RTP port\n");
             err = AVERROR(EIO);
             goto fail;